Fluid-pressure gage and automatic regulator.



A; c. HU-LBERTQ FLUID PRESSURE GAGE AND AUTOMATIC REGULATOR. APPLIOATIOII'ILBD DB6. 27;1B12.

1,069,066. Patented July 29, 1913.

2 SHEETS-SHEET 1.

mvamok M C. 1W:

ATTORNEY sTAT s AHSEL c. EULBERT, or SAN F esnel shop ola'nrronnra.rnurnsrnnssunn GAGE AND au'roma'rro'nnounaron.

Specification of Letters Patent.

Patented July 29, 1913.

vApplication filed December 27, 1912. Serial No. 738,792.

To all whom it may concern:

Be it known that I, Ansel. C. Hummer, a citizen of the United States,residing at San Francisco, in the county of San Fran .cisco and State ofCalifornia, have invented new and useful Improvements in Fluid- PressureGages and Automatic Regulators, of which the following is aspecification.

One object of the present invention is to provide a fluid pressure gagewhich will be accurate, compact in form, simple in construction, and notliable to get out of order.

the gage whenused as an automatic regulator; Fig. 8 .is a view of thesame similar to Fig. .3.

Referring to the drawing, 1 indicates a pressure chamber casing formedwith a depending central internally threaded apertured boss 2, adaptedto be screwed on to the end of a pipe connected with a source of supplyof pressure fluid, such as steam, and

Y chamber.

3 indicates a spring casing, the casings l and 3, constitutlng atwo-part housing for the diaphragm. Between circular flange portions ofsaid casings is clamped, by bolts 4, a marginal portion of a diaphragm6, the construction of which will be hereafter more specificallydescribed, and which diaphragm forms a fluid-tight closure for thepressure Centrally riveted to said diaphragm on the upper side thereofis a bearing-block 7 forming a lower seatifor a coiled spring 8, theupper end of' which abuts against an upper seat 9 in the top of saidspring casing. Into a central threaded hole in said top is screwed aplug 11, the under surface of which contacts with said upper seat 9, sothat by. screwing said plug in or out, the spring can be more or lesscompressed, and its pressure varied as desired. To transmit a verticalmotion of said diaphragm, due to a change in the fluid pressure, thereis provided-a rod 12 constituting an actuating -membe1", the lower endof which bears upon said lower seat 7, and

which passes t rough central apertures in said upper seat and plug, and.the upper portion of whichpasses through a guideway 13 formed in an arm14 extending upwardly from a spring casing, said rod being maintamed incontact with said lower seat by a coiled spring 16 surrounding the rod,and compressed between said bearing and a transverse pin 17 through saidrod. The actuating member is therefore yieldingly held in contact withthe diaphragm during all vibrations' thereof. To said rod is rigidlysecured as shown at 18, a cross arm 19, of which one end is guided in avertical slot 21 formed in the arm 14, while the other end is pivotallysecured to the lower end of a link 22, the upper end of which ispivotally connected to a lever 23. Said lever is fulcrumed, as shown at24, in a bracket 26, rigidly secured to a cross bar 27, secured byscrews .28 to lugs 29 formed integral with, and extending inwardly from,the cylindrical wall of a gage casing 31, said casing havinga dependingportion 32 surrounding the spring casing, and secured by screws 33passing through flanges 34 to the flange portion of said spring casing.A rear circular wall 36, Fig. 3 of said gage casing is secured theretoby means of screws 37 screwed into lugs-38 formed integral withsaidcasing. The free end of said lever is formed with a segment gear 39,which meshes with a pinion 41 on a shaft 42 having a front bearing inthe cross bar 27 and a rear bearing in a bracket 43 secured to, andextending rearwardly from, said cross bar, said shaft passing through adial plate 44 having secured thereon on the end thereof the center of apointer 46 rotating in front of said dial plate. When used to indicatethe pressure of steam, said dial has thereon preferably two circularindicating scales, one '47 to indicate the pressure. in pounds to thesquare inch, and the other 48 to indicate the temperature in degrees.These two series are so arranged that, while one end of the pointertravels over the pressure scale 47, the other end travels over thetemperature scale 48. This arrangement is very useful when the steam isused for cooking, vulcanizing, or other purposes in which a knowledge ofthe exact temperature is important. The extent of the temperature scalewill corr 0nd to the limits of temperature within which it is desired touse the-apparatus. It is here shown'asjranging betweeniaiiout-290? F.and 340s The mode of operation of the defies 'will be readily understoodfrom the foregoing description. As the fluid pressure increases, the rod12 is raised rocking1 the lever-2 3{.and correspondingly rotating t epinion'ii il and moving the pointer over the indicatingdial.

A very important feature of my invention resides in the construction ofthe diaphragm, whereby I am enabled to obtain a largeamplitude oftransverse movement of a diaphragm of comparatively small diameter. Saiddiaphragm comprises a flange portion 51 secured between the casings '1and-3, a short conical portion 52 within said flange portion, and,within said conical portion a concavo-convex central portion 53. If thefluid pressure is at its maximum value,' then the diaphragm will be inthe position illustrated in Fig. 4. As the fluid pressure decreases, sothat the pressure of the spring depresses the diaphragm, theconcave-convex central portion is moved from the position shown 1n Fig.4: to the position shown not materially change'its position. But, as

- the fluid pressure still further decreases, no

appreciable change takes place in the formation of the concavo-convexcentral portion 53, but the conical' portion 52 approaches a flattenedcondition, its inner edge, and the outer edge of the concavo, convexportion, contracting. This double curvature'of the diaphragm permits ofa much greater amplitude of transverse movement of the center of thediaphragm than one in which the curvature i'ssingle.

In the modification shown in Figs. 7 and 8, there extends through therod 12 a pin 54, which, as the rod rises to any desired height, that is,when the pressure is of any desired degree, engages an insulating block56 carried by a lever pivoted at 57 upon a casting 58, to which may beattached by a binding screw 59 one side 60 of an electric circuit. Saidlever carries a weight 61, and

its end can rest upon a contact screw 62 screwed through aIbracket 63,carrying a binding screw 64 to- .-which the other side 65 of saidcircuit can be attached. The bracket 63 and casting 58 are secured byscrews 66 to opposite sides of the gage casing, but insulated therefromby insulating material 67. When the fluid pressure rises beyond apredetermined degree, the lever is raised from oflt' the contact screw62 and the circuit is broken, and the circuit closes again when thepressure again falls below said degree. By this means, therefore, thefluid pressure can be automatically regulated very accurately, since theelectric circuit can be used to control said pressure, the pressureincreasing when the circuit is closed and decreasing when it is broken.For the purpose controller regulates the fluid pressure, I

have shown conventionally a steam generator 70- in which the steam isgenerated b an electric heater 71, which is in circuit wit an electricgenerator 72, and connected to the circuit controller of the pressuregage. The contact 62 is adjusted so that the lever will be lifted tobreak the circuit at the desired pressure. As soon as the critical fluidpressure is reached the circuit will be broken at the contact 62,thereby cutting out the electric heater and preventing a further rise inpressure. As soon as the pressure decreases the lever 55 will againclose the circuit at 62, bringing the electric heater into operation,so'that the pressure gage automatically controls the fluid pressure ofthe system. The lever-arm 55 projects outside of the casing and thecotiperating contact stud 62, is also located outside of the casing inan open frame 63. Now as these arts are adjusted so that the arm 55 isli ted from the stud 62 at the instant the fluid pressure reaches itsmaximum predetermined limit, it is apparent that the projecting arm 55constitutes a maximum-pressure indicator and a glance at the position ofthe arm 55 will show whether the fluid pressure of the system hasreached the maximum limit or whether it is below the maximum. Inasmuchas the arm 55 is operated by the same actuating member as the dialpointer, the indication of the maximum limit is exceedingly sensitiveand accurate.

It is well known that the ordinary pressure gage, in which a Bourdon, orC spring,

is used, does not retain its accuracy for any great length of time; alsothat when such spring is used to operate an electric circuit breaker,the pressure surface operating the gage is so small that the necessarypower is sometimes lacking. With this invention the surface exposed topressure and operating the gage is considerable.

By my invention I am enabled to provide a pressure gage of extremeaccuracy, the base of which has a diameter ofnotmore than two andone-half inches, :1 result never before attained, or even approximateisofar as I am aware, the smallest diameter of a diaphragm gage heretoforeput upon the market being one having a base of at least twice thediameter. This result I attain by the following three improvements:

1. The peculiar form of the diaphragm, comprising the conical portion 52making an angle of about twenty-five degrees with the flange 51, and thecentral portion 53, which may be either concave or convex. This conicalportion 52 permits of the portion 53, as shown in Fig. 5, being stillfurther depressed to the position shown in Fig. 6. Thus I obtain adiaphra tude of movement for a given diameter.

of great ampli- 2. With my construction the spring 8 is allowed toexpand to its full extent in the position in which there is no pressureupon the under side of the diaphragm. In prior devices as for instancein the patent to Craig,

No. 908,206 the normal positlon of the diais not possible to obtain adiaphragm of absolutely equal strength on all sides. Consequently if thestem -12 were positively connected to the seat 7, there would be atendency to sidewise movement of said stem,.

owing to the diaphragm being. weaker on one side than on another. Thiswould cause the stem to bind in its bearing. By the construction 'inwhich the stem merely rests upon the seat, this result is avoided.

I am aware that it has been proposed to use both pressure andtemperature scales with the same pointer, but heretofore, so far as I amaware, these scales have extended in two concentric circles having thesame angular relation to the pointer. When such is the case it is notpossible to prevent the readings of the smaller circle bein obstructedby the pointer. In my invention in which they extend opposite to oneanother the readings 1. A pressure gage, comprising a diaphragm having acentral concavo-convex portion terminating in an outwardly inclinedannular portion extending in the same general direction as theconcavo-convex portion uponone side of the plane of the diaphragm and aflat marginal rim adjacent said inclined portion and a casingsurrounding said diaphragm havingclamping means for engaging saidmarginal rim.

2. A pressure gage, comprising a diaphragm having its margin restrainedand its central portion. free to move under the inare never obstructed.

fluence of fluid pressure acting against one side thereof, aspringnormally maintaining a tension upon the other side ofthediaphragm, a device for indicating variations 'of pressure, anactuating member operatively connected to said indicating device andhaving one end loosely engaging said diaphragm upon the side of thetension member, and means for adjusting the tension of said springindependently of said actuating member.

3. A pressure gage, comprising a diaphragm having its margin restrainedand its central portion free to move under the influence of fluidpressure acting against one side thereof, an adjustable tension deviceengaging the opposite side of the diaphragm, an indicating device, anactuating member op eratively connected to said indicating de vice andbearing loosely upon the diaphragm upon the side of the tension member,yielding means acting directly upon said actuating member and tending tomaintain said member in contact with the diaphragm in all posit-ionsthereof and return the indicating device to zero position when the fluidpressure is removed, and means for adjusting said tension deviceindependently of said actuating member.

4. A pressure gage, comprising a housing, a diaphragm within the housingand having its marginal rim clamped therein, a bearing-block carried bysaid diaphragm, an adjustable spring engaging said block, means I foradjusting the tension of said spring, an indicating device, and aspringpressed stem or rod operatively connected with saidindicating-device and having one end bearing loosely upon saidbearingblock.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

ANSEL O. HULBERT.

Witnesses:

F. M. WRIGHT D. B. Rronanns.

